Multicolor screen for photography



Feb. .20, 1923. 1,446,049

l. K|TsE|:

MULTICOLOR SCREEN FOR PHOTOGRAPHY Filed Dec. 81 1918 l ll lll-LLI.

III

-mmm- Patented Feb.. 20, 1923.

Isinoa Kr'rsnn, or PHILADELPHIA, PENNSYLVANIA.

l MULrIcoLonscnnnn ron PHOTOGRAPHYQ@ Application 'filed December 31, 1918. Serial No.269,059. l

To all whom t 'may concern 1- f Be it known that I, Isnion Krrsnn, a citizen of the United States, residingat Philadelphia, in the county ofPhiladelphia and l-State of Pennsylvania, have invented certain new and useful Improvements in Multicolor Screens for Photography, of which the following is a specification. Y j

My invention relates to an improvement in color screens for photography.

Its object is to produce a color screen in-v tegral with a photographic blank.

In the accompanying drawing I have-illustrated the different steps for producing a multi-colored screen on a moving picture film, but it is obvious that this my invention may also be used for still pictures.

In the accompanying drawing the Figs.

l to 7 inclusive are plan views, illustrating i part of a moving picture film in the process of preparing the same with a color screen.

I will now describe the mode or method of procedure in obtaining the required result,

and in doing so I will refer tothe different numbers as indicating the diiferent parts of these figures, and I will here describe this my invention as being applied to moving picture films.

Moving picture films are today produced of dissolved cellulose, such for instance as is known in commerce as Celluloid j In Fig. l this film or rather part of same is indicated by l', and the perforations with which these films are usually provided by;

l?, as the first step in producing the color screen `I provide the 'surface of lmvl rwith a gelatine, preferably chromated and indi-4 .cated in Fig. 1 by 2. The film which is now sensitized with this chromated gelatine, is subjected to the action of light under a pattern, consisting of a transparent base and opaque lines laterally drawn across the `face of the pattern. It is well understood by persons versed in the art, that it' a blank or film sensitized with chromated gelatine is subjected to the action of rays of light in conjunction with a pattern, consisting inV part of transparent and in part of opaque niaterial those parts of the blank or film coinciding with the transparent part of the pattern, during the time that the blank or.

film is subjected to the rays of light, undergo a chemical change whereby the gelatine so acted upon by the light is made to a great extent insoluble in tepid water, whereas those parts of the blankvor film, coinciding the time that this'blank or film is subj ected to the rays of light, will remain unaffected byi said rays `and are therefore readilyl removed byl tepid water. Whenthereforefafilm, such yas is illustrated'in Fig. l, issub# jected through a transparentpattern with. suitable laterally drawn lines of opaque ma!v` terial to the raysof lightand then subjected to the washing'out process, the `surfaceof` i tiene y ing with the opaque partuof the pattern, ldurthe film will consist of laterallines of gel-aff` l,

tine, alternating with 4lines of exposed cel luloid, as is clearly indicated in Fig. 2in

soluble in acetone, which, fortunately is also a part solvent of thecelluloid Yout of Which 'l the iilm proper consists. In practise I have found it necessary to decrease'the dissolving properties of the acetone'on' the, Celluloid,

asotherwise'even a few seconds7 exposurefofv the bare; Celluloid to `the acetone-dye, will i geratly injure the film fandmake "thesame useless for my purpose. The ma'terialwto decreasethe reaction, has to be yoflsuch fa ynature as not to aect theidyed gelatine; andl f if possible even to add to therepel'lingI prop-`r erty ofthe acetone. After prolonged experi! ments `I have found that carbon tetrachlorid y isvel'yjwell adaptedyfor'this purpose., It isl true, that to some extent formaldehyde Vmay be substituted for carbon tetrachlorid.y but yet I have found the action of carbon tetrachlorid farmore practical than that of form# aldehyde. Different colorsv may ,be 'usephv Y ,j

but I have here shown the Celluloid as' being colored with a suitable red, and Fig. 4L 'indi- Gates substantially the appearance vof thefilml after this step, and iuthis gure5 indicates the colored gelatine, and I use the number f 6 to indicate the now colored Celluloid. It has tobe statedthat the dye solutionl in its entirety is repelled bythe gelatine andthe gelatine therefore will not take up thejcolor` of this solution and vwill' reinainabsolutely' unaffected by same.

After the completion of the coloring process of the Celluloid, the whole surface of the film is provided with a layer of varnish. it is preferred and in reality required that this varnish should not be affected by the later process of dyeing or coloring one or `the other parte of the film. In Fig. 5, l0 clearly indicates the coating of Varnish, partly `broken away so as to show the underlying colors.

The next step is, to expose the Celluloid of the film proper longitudinally at different laces, that is to free the underlying celluloid from the gelatine and varnish in longitudinal lines properly spaced from each other. This proceeding may easily be accomplished with the aid of a device, pro-- vided with a series of properly sharpened points or cutting edges, Fig. 6 illustrates these lines and in this ligure these lines are indicated by 7 5 illustrating the continuous lines of the exposed Celluloid. lt has to be stated, that in Clearing or cutting away the colored gelatine overlying the Celluloid film, the colored lines ,6 of the celluloid proper will not be injuriously affected, if the cutting is not deep enough to cut the film itself; for the reason that the special dye above described, `to tint the exposed Celluloid, impregnates the saine to a. comparatively great depth For this reason the empty or uncolored spaces of the lines 7, alternate with the colored rspaces of the Celluloid. These exposed lines of celluloid are then impregnated with any of the required colors here shown as consisting of a blue dye and thesev lines, properly dyed in the blue color are indicated in. Fig. 7 by the numeral S. rlhe whole surface of the filml therefore consists cfa series of iigurations, here squares, the sqare of one color alternatingn with the square of a second color.

I have illustrated and described, a. process with the aid of which three colors may be applied to the surface of a suitabley blankv or film, without in the least producing undue interference between one color and the other color. But in reality, the screen presents not only the'three colors applied to the film but it represents a fourth color, being the effect of the combined two colors red and blue at the intersection of the lateral red and longitudinal blue lines; vand if these two colors are proper in relation or balance as to each other, thev will produce a violet or blue violet, fortunately just the color required in all color screens and not present in any of them. These junctions of the two colors, of the red (6) of the lines t, and the blue (8) of the lines 7, producing` as they do the violet color, are indicated by 9.

The screen therefore comprises, the four colors red, green, blue and violet, embracing in their Combinations the whole spectrum.

Having now described my invention, what l Claimv as new and desire to secure by' Letters Patentis l. In the production of multi-colored screens for moving` picture films the steps as follows Surfacing a Celluloid film with bichromated gelatine, producing from said gelatine, with the aid of light raysffigurations on the surface of said film, tinting said figurations with one color, impregnating then the exposed Celluloid with a second color, coveringthe surface of the gelatine and exposed Celluloid with a varnish, removing part of the varnish and gelatine and impregnating` the so exposed part of the Celluloid with a third color.

2. ln the method of producing a multicolored screen integral with the Celluloid support the steps which consists in first sensitizing the Celluloid support with a bichromated gelatine, photographing on said sensitized support iigurations with the aid of a suitable matrix, washing' out the gelatine not exposed to the light rays during the photographic process, tinting the remaining gelatine with -a material not affecting the Celluloid proper,and then subiecting` the exposed Celluloid to a tinting solution not affecting the gelatine.

ln testimony whereof l aflix my signature in the presence of two witnesses. Y ISIDOR .llrlll` Witnesses:

E, E. Minima, JOHN J. RUTHERFORD. 

